Acrolein-urea condensation products and process of producing same



Patented Jan. 12, 1943 m m ner-min, Nee York, N. Y, assignor a Iacrolein Corporation,- a corporation or Dela:

Application April sci-u No. 328,029",

' This invention relates to new 1 condensation products produced fromacroleinia id urea. ,The

invention includes :not only newacroIeIn-urea amine. diethylenetriamine, etc.

condensation products and new molded products used in the second stageof the condensation. may be an organic or an inorganic base, or a salthaving a basic reaction. Among such materials which may be used withadvantage are potassium or sodium hydroxide, piperidine, triphenyl am-55 .moniumhydroxide, trimethyl phenyl ammonium hydroxide, methyl andethyl amines, ethylene di- ;The proportions of acrolein andiurea used inmade therefrom, but also the processbywhich I producingthenew productsmaybe varied, tiethe newcondensation products-.areproduced. r pendingsomewhatiupon the type of final con- Thenewacrolein-ur'ea condensationproducts densation productdesired. In general, an inarewhite,opaquesolids." They arethermoplastic crease in'theproportion of acroleinto. urea-rein nature and -may-be advantageously molded suits in theproduction-o1 harder condensation I with or without fillers orcolorln'gfmatter into products having increased water resistance. Theproducts of any desirable shape... ;'l'he -molded total amount of.acrolein-reacted with urea in products, in the absence of added coloringmateproducing the new condensation. products may rials, are clear,transparent, amber-colored solids advantageously beas littleas about twoparts oi excellent water resistant properties, By the by weightof-acrolein ioreachpart by weight of use of suitable plasticizersmolded-products o1 l5 urea. and it'may be as :highas about four parts,very desirable toughness and mechanical I or somewhat more, of acroleinfor each part or strength may be produced. The new acroleinurea. ureacondensation products may also be mixed The amount of acrolein reactedwith urea durwith other natural or synthetic resinous mateing thevarious stages of the process is adrials to produce composite moldedplastics. vantageously so proportioned that the reaction In producingthe new acrolein-urea condensaproduct produced in the first or initialacid stage tion products by the new process of the invention, is capableof reacting with a further quantity acrolein is caused to react withurea in three of acrolein-in the second or alkaline stage, the stagesunder conditions such that the first stage amount of acrolein addedduring the second is acid, the second is alkaline, and the third is stge ein such that the reaction Pr duct Of the again acid. Thus inpracticing the new process, second stage is capable of reacting with afurther acrolein is caused to react with urea in an acid quantityof'acrolein during the final acid stage. medium, the resultingreactionmixture then be- The amount of acrolein added in the first stageing made alkaline and caused to react with an of the condensation isadvantageously about oneadditional quantity of acrolein, and theresulting half the weight of the urea. In the second or alreactionmixture then being made acid and kaline stage the amount of acroleinadded is adcaused to react with a further quantity of vantageously atleast about equal to the weight acrolein to produce the new condensationprodof urea used in the first stage, although the nets of the invention.amount of acrolein may advantageously be con- In carrying out the newprocess the acidity, siderably more. In the third stage, that is thedurlngthe first and third stages of the confinal acid stage, the amountof acrolein added densation,is advantageously such that the pH may be aslittle as about one-half the weight value is less than about 5.Any'suitable acid may of the urea used in the first stage, but it mayadbe used to produce such acidity, for example, hyvantageously beconsiderably more. drochloric acid, phosphoric acid, sulphuric acid, 40The acrolein reacted with the urea during the nitric acid, benzoic acid,etc., may be used with various acid and alkaline stages of the processadvantage. The acid used in the first stage of may be added in smallincrements during the the condensation need not be the same as theseveral stages; The alkaline or acid materials acid used in the thirdstage. used to change the pH of the reaction mixtures During the second,or alkaline, stage of the maybe similarly added. Thus, for example, itis condensation the pH value is advantageously advantageous inpracticing the alkaline stage of more than about 8. In general, too higha dethe process to alkalinize the reaction mixture gree of alkalinity isnot desirable since the conproduced in the first stage and then add aregudensation reaction becomes difiicult to control lated amount ofacrolein thereto, the resulting under such conditions. The alkalinematerial reaction mixture being then treated with a further quantity ofan alkaline material and an additional amount of acrolein. The acidstages of the process maybe practiced in the same manner.

In order to promote the homogeneity of the causing acrolein and urea toreact in an acid medium, thereafter rendering the resulting reactionmixture .alkaline and causing it to react with a further quantity ofacrolein, thereafter rendersolution containing about 150 cc. of water,about 1 added to this solution whereupon a reaction commences. Thereaction is exothermic in nature and the temperature rises toapproximately 50 C. At the end of about fifteen minutes the reaction issubstantially complete and, the reaction product is a clear, viscoussolution.

To this reaction product is added about 10 cc. of a solution ofpiperidine. About 150 cc. of acrolein are then added, causing a furtherreaction to take place. Again the reaction is exothermic in nature andthe temperature rises to about 60 or 70 C. When the reaction issubstantially complete the temperature begins to fall and theodor ofacrolein also disappears. The reaction product is a turbid, quiteviscous solution.

5 cc. more of the 5% piperidine' solution are then added to the reactionmixture together with 100 co. more of acrolein. A further reactionensues and the reaction product is a turbid, viscous v liquid.

About cc. of an 8% phosphoric acid solution are added to the reactionproduct, and thereafter about 200 cc. of acrolein arealso added. Thereaction mixture becomes clear and without giving off any appreciablequantities of heat sets to a clear, transparent, colorless gel in aboutthree or four hours. After standing about ten or twelve hours the gel istransformed into a white, opaque, brittle solid.

In order to use this reaction product for th production of moldedarticles,it is broken up and dried at about 65 C. The dried condensationproduct is then advantageously molded by subjecting it to about 5,000lbs. pressure at a temperatureof about 250 F. for about five minutes.The molded product'is a hard, tough, ambercolored material of excellentwater resistance. Exposing a sample of the product to boiling water forone-half hour does not cause any appreciable softening of the product.

In producing molded articles from the new acrolein-urea condensationproducts, various coloring materials may be introduced into the reactionmixture durin the acid or alkaline stage of the process, or if desiredthe coloring materials may be admixed with the condensation product justprior to the molding operation. Fillers may also be mixed with theacrolein-urea condensation product.

'The new acrolein-urea compositions may be plasticized with any suitablematerial. Among materials which may advantageously be used for thispurpose are acetanilide. benzaldehyde, methyl isobutyl ketone, etc.About 5% by weight of acetanilide may be used with particular advantage.Glycols may also be used, but they tend to decrease the water resistanceof the products.

ing the resulting reaction mixture acid and cansing it to react with anadditional quantity of acrolein.

2. The process of producing condensation products from acrolein and ureawhich comprises causing acrolein and urea to react in an acid medium,thereafter rendering the resulting reaction mixture alkaline and causingit to react with a further quantity of acrolein, thereafter furtheralkalinizing the resulting reaction mixture and causing it to react witha further quantity of acrolein, thereafter rendering the resultingreaction mixture acid and causing it to react with an additionalquantity of acrolein. n

3. The process of producing condensation products from acrolein and ureawhich comprises causing acrolein to react withurea in a medium having apH less than about 5, therafter adjusting the pH of the resultingreaction mixture so that it is more than about 8and causing the reactionmixture to react with a further quantity of acrolein, thereafteradjusting the pH of the resulting reaction mixture so that it is lessthan about 5 and causing the reaction mixture to react with anadditional quantity of acrolein.

4. The process of producing condensation products from acrolein and ureawhich comprises causing about one part by weight of urea to react withabout one-half part by weight of acrolein in an acid medium, thereafterrendering the resulting reaction mixture alkaline and causing it toreact with at least about one part by weight of acrolein, thereafterrendering the resulting reaction mixture acid and causing it to reactwith at least about one-half part by weight of acrolein.

5. The process of producing condensation products from acrolein and ureawhich comprises causing about one part by weight of urea to react withabout one-half part by weight of acrolein in a medium having a pH lessthan about 5, thereafter adjusting the pH of the resulting reactionmixture so that it is more than about 8 and cansing said reactionmixture to react with at least about one part by weight of acrolein,thereafter adjusting the pH of the resulting reaction product so that itis less than about 5 and causing said reaction mixture to react with atleast about one-half part by weight of acrolein.

6. Acrolein-urea condensation products produced by the process set forthin claim 1.

7. Acrolein-urea condensation products produced by the process set forthin claim 2.

8. Acrolein-urea condensation products produced by the process set forthin claim 3.

9. Molded acrolein-urea, condensation products produced from theproducts made by the process set forth in claim 1.

10. Molded acrolein-urea condensation products produced from theproducts made by the process set forth in claim 2.

l1. Molded acrolein-urea condensation products produced from theproducts made by the process set forth in claim 3.

KARL M. HERSTEIN.

